Aerosol generation

ABSTRACT

An aerosol generating article for use in an aerosol generating assembly, the aerosol generating article including an aerosol generating substrate having an aerosol generating material, wherein the aerosol generating material is solid and includes a starch and a plasticizer, wherein the amount of plasticizer is from about 5% to 70% by weight of the starch.

PRIORITY CLAIM

The present application is a National Phase entry of PCT Application No. PCT/EP2020/071647, filed Jul. 31, 2020, which claims priority from Great Britain Application No. 1910952.9, filed Jul. 31, 2019, each of which is hereby fully incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to aerosol generation.

BACKGROUND

Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Alternatives to these types of articles release an inhalable aerosol or vapor by releasing compounds from a substrate material by heating without burning. These may be referred to as non-combustible smoking articles or aerosol generating assemblies.

One example of such a product is a heating device which release compounds by heating, but not burning, a solid aerosolizable material. This solid aerosolizable material may, in some cases, contain a tobacco material. The heating volatilizes at least one component of the material, typically forming an inhalable aerosol. These products may be referred to as heat-not-burn devices, tobacco heating devices or tobacco heating products. Various different arrangements for volatilizing at least one component of the solid aerosolizable material are known.

Another known type of aerosol generating assembly is an electronic cigarette or e-cigarette. In these devices, a liquid or gel aerosol generating material is heated without burning. This vaporizes one component of the material to form an inhalable vapor or aerosol. The liquid or gel material may comprise nicotine.

As another example, there are e-cigarette/tobacco heating product hybrid devices, also known as electronic tobacco hybrid devices. These hybrid devices contain a liquid source (which may or may not contain nicotine) which is vaporized by heating to produce an inhalable vapor or aerosol. The device additionally contains a solid aerosolizable material (which may or may not contain a tobacco material) and components of this material are entrained in the inhalable vapor or aerosol to produce the inhaled medium.

SUMMARY

A first aspect of the invention provides an aerosol generating article for use in an aerosol generating assembly, the article comprising an aerosol generating substrate comprising an aerosol generating material, wherein the aerosol generating material is solid and comprises a starch and a plasticizer, wherein the amount of plasticizer is from about 5% to 70% by weight of the starch.

A second aspect of the invention provides an aerosol generating assembly comprising an aerosol generating article according to the first aspect and a heater which is configured to heat but not burn the aerosol generating material.

A third aspect of the invention provides starch matrix material comprising;

-   -   a plasticizer wherein the amount of plasticizer is from about 5%         to 70% by weight of the starch; and     -   a plant-derived flavor or aroma component.

A fourth aspect of the invention a kit comprising an aerosol generating article according to the first aspect and a device which is configured to receive the article in use, the device comprising a heater which is configured to heat but not burn the aerosol generating material in use.

A fifth aspect of the invention provides a method of making an aerosol generating article according to the first aspect, the method comprising;

(i) mixing the constituent parts of the aerosol generating material in a slurry, heating and stirring the slurry to effect gelation, casting the gel and drying by heating to form the aerosol generating material; and

(ii) incorporating the aerosol generating material in an aerosol generating article.

The invention also provides a slurry comprising:

-   -   a starch;     -   a plasticizer wherein the amount of plasticizer is from about 5%         to 70% by weight of the starch; and     -   a plant-derived flavor or aroma component; and     -   water.

Suitably, the weight ratio of water to the total weight of the other ingredients is between about 10:1 and 20:1.

The invention also provides a slurry comprising:

-   -   a starch;     -   a plasticizer, wherein the amount of plasticizer is from about         5% to 70% by weight of the starch;     -   a powdered tobacco material having a mean particle diameter of         less than about 250 μm, wherein the amount of powdered tobacco         material is from about 40% to 300% by weight of the starch;     -   water, wherein the weight ratio of water to the total weight of         the other ingredients is between about 10:1 and 20:1.

The invention also provides a slurry comprising

-   -   a starch;     -   a plasticizer, wherein the amount of plasticizer is from about         5% to 70% by weight of the starch;     -   an aqueous tobacco extract, wherein the weight ratio of the         aqueous tobacco extract to the total weight of the other         ingredients is between about 10:1 and 20:1.

Further aspects of the invention include;

-   -   (i) a wrapper for a smoking article or aerosol generating         article, wherein the wrapper comprises a starch matrix and a         plasticizer, wherein the amount of plasticizer is from about 5%         to 30% by weight of the starch; and     -   (ii) a filter for a smoking article or aerosol generating         article, the filter comprising a starch matrix and a         plasticizer, wherein the amount of plasticizer is from about 5%         to 15% by weight of the starch.

The invention also provides articles including the above wrapper and/or filter.

Further aspects, features and advantages of the invention will become apparent from the following description, given by way of example only, and with reference to the accompanying figures. Features described herein in relation to one aspect are explicitly disclosed in combination with other aspects of the invention, to the extent that they are compatible.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a section view of an example of an aerosol generating article.

FIG. 2 shows a perspective view of the article of FIG. 1.

FIG. 3 shows a sectional elevation of an example of an aerosol generating article.

FIG. 4 shows a perspective view of the article of FIG. 3.

FIG. 5 shows a perspective view of an example of an aerosol generating assembly.

FIG. 6 shows a section view of an example of an aerosol generating assembly.

FIG. 7 shows a perspective view of an example of an aerosol generating assembly.

DETAILED DESCRIPTION

The aerosol generating material described herein is “solid”. However, it may be a solid that retains within it some fluid such as liquid. The solid may be a gel. It may be referred to as a “dried gel”. It may also be referred to as a “starch matrix”.

As described above, the invention provides an aerosol generating article for use in an aerosol generating assembly, the article comprising an aerosol generating substrate comprising an aerosol generating material, wherein the aerosol generating material is solid and comprises a starch and a plasticizer, wherein the amount of plasticizer is from about 5% to 70% by weight of the starch.

The inventors have found that materials having this composition can be efficiently heated to generate an inhalable aerosol.

Starch forms a helical structure and small molecules such as flavors and aromas are able to bind within this helix. However, release of these molecules requires the helix to be heated so that it unwinds. The aerosol generating material described herein is formed by heating and dissolving starch and mixing with a plasticizer. This plasticizer embeds within the starch. As the starch then cools, retrogradation (realignment into the crystalline helical form) is inhibited by the glycerol, resulting in an irregular starch matrix which the small molecules can bind to. The release temperatures for these small molecules is lower than for the regular crystalline structure.

The inventors have established that such starch matrix materials (comprising plasticizer in the claimed range) are suitable for use as aerosol generating materials in non-combustible smoking articles.

Any starch may be used in the invention. Suitably, the starch may be a soluble starch, suitably a non-modified soluble starch. Suitably the starch may be a derived from a gluten-free product. The starch may comprise potato starch. This material is readily available. The inventors have established that the use of starch as a matrix material is preferable as compared to other materials such as alginates and pectins, since these other components require the addition of a setting agent (e.g. a calcium source) to form the matrix; starch requires no such additional agent. Alginates and pectins also contribute off-notes to the flavor/aroma of the generated aerosol, and the use of starch as the matrix material has been found to reduce this effect. Starch also has a higher loading capacity. Starch materials are also typically less tacky than comparable alginate or pectin materials, easing manufacture and handling.

The amount of plasticizer is from about 5% to 70% by weight of the starch. Suitably, the amount of plasticizer may be from about 5%, 10%, 15% or 20% to about 70%, 60% or 50% by weight of the starch. If the plasticizer content is too low, the resulting matrix may be brittle, and/or the starch helical structure may be relatively ordered meaning that any small molecules bound in the helix may be difficult to release in use. Conversely, if the plasticizer content is too high, the resulting matrix may be tacky and difficult to handle, and/or the matrix may be so disordered that any bound small molecules are released too readily in use. Further, if the content of the plasticizer is too high, the material may absorb water (as the plasticizer is hygroscopic) resulting in a material that does not create an appropriate consumption experience in use.

Further, the plasticizer content specified herein provides an aerosol generating material with a flexibility that allows a sheet of the material to be wound onto a bobbin, which is useful in manufacture of aerosol generating articles.

In some cases, the plasticizer may be an aerosol generating agent. Suitably, the plasticizer comprises one or more compound selected from erythritol, sorbitol, glycerol, glycols such as propylene glycol, monohydric alcohols, high boiling point hydrocarbons, lactic acid, diacetin, triacetin, triethylene glycol diacetate, triethyl citrate, ethyl myristate, isopropyl myristate, methyl stearate, dimethyl dodecanedioate and dimethyl tetradecanedioate. Suitably, the plasticizer may comprise one or more of erythritol, propylene glycol, glycerol, triacetin, sorbitol and xylitol. In some cases, the aerosol generating agent comprises, consists essentially of or consists of glycerol.

The aerosol generating material may, in some cases, be a hydrogel and comprises less than about 20 wt %, 15 wt %, 12 wt % or 10 wt % of water calculated on a wet weight basis (WWB). In some cases, the material may comprise at least about 1 wt %, 2 wt % or 5 wt % of water (WWB). In some cases, the amorphous solid comprises from about 1 wt % to about 15 wt % water, or from about 5 wt % to about 15 wt % calculated on a wet weight basis. Suitably, the water content of the amorphous solid may be from about 5 wt %, 7wt % or 9 wt % to about 15 wt %, 13 wt % or 11 wt % (WWB), most suitably about 10 wt %. This water level ensures that the material is relatively resistant to microbial degradation (such as mold growth).

The aerosol generating material may further comprise a plant-derived flavor or aroma component. In some cases, this may be a powdered plant-derived component, and may have a particle size of less than about 250 μm, suitably less than about 200 μm or 150 μm (that is, the powder has been sieved and passes through a sieve with that pore size). In some cases, the powder may have a mean particle diameter of less than about 250 μm, suitably less than about 200 μm or 150 μm. The inventors have found that if a powder is incorporated into the matrix structure, it is desirable to have a particle size as specified —a larger particle size disrupts the starch matrix and any bound small molecules are released too readily in use.

The amount of the powder component may suitably be from about 40% to about 300% by weight of the starch, more suitably from about 50% to about 200% or 100% by weight of the starch.

In some cases, the amorphous solid comprises an active substance. For example, in some cases, the amorphous solid comprises a tobacco material and/or nicotine. For example, the amorphous solid may additionally comprise powdered tobacco (having a particle size (or mean diameter) as discussed above) and/or nicotine and/or a tobacco extract. In such cases, nicotine and/or tobacco aroma/flavor components of the extract may be bound to the starch. In some cases, the amorphous solid may comprise from about 1 wt %, 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt % to about 80 wt %, 70 wt %, 50 wt %, 45 wt % or 40 wt % (calculated on a dry weight basis) of active substance. In some cases, the amorphous solid may comprise from about 1 wt %, 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt % to about 80 wt %, 70 wt %, 60 wt %, 50 wt %, 45 wt % or 40 wt % (calculated on a dry weight basis) of a tobacco material and/or nicotine.

In some cases, the amorphous solid comprises an active substance such as tobacco extract. In some cases, the amorphous solid may comprise 5-60 wt % (calculated on a dry weight basis) of tobacco extract. In some cases, the amorphous solid may comprise from about 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt % to about 55 wt %, 50 wt %, 45 wt % or 40 wt % (calculated on a dry weight basis) tobacco extract. For example, the amorphous solid may comprise 5-60 wt %, 10-55 wt % or 25-55 wt % of tobacco extract. The tobacco extract may contain nicotine at a concentration such that the amorphous solid comprises 1 wt % 1.5 wt %, 2 wt % or 2.5 wt % to about 6 wt %, 5 wt %, 4.5 wt % or 4 wt % (calculated on a dry weight basis) of nicotine. In some cases, there may be no nicotine in the amorphous solid other than that which results from the tobacco extract.

In cases where the amorphous solid includes a tobacco extract, it may be an aqueous extract, obtained by extraction with water. In some cases, the tobacco extract may be within the plasticizer as a solvent (i.e. obtained by extraction using the plasticizer). The tobacco extract may be an extract from any suitable tobacco, such as single grades or blends, cut rag or whole leaf, including Virginia and/or Burley and/or Oriental. It may also be an extract from tobacco particle ‘fines’ or dust, expanded tobacco, stems, expanded stems, and other processed stem materials, such as cut rolled stems. The extract may be obtained from a ground tobacco or a reconstituted tobacco material.

In some cases, the aerosol generating material may comprises a flavorant. In some cases, the flavor (if present) comprises, consists essentially of or consists of menthol. Suitably, the amorphous solid may comprise up to about 60 wt %, 50 wt %, 40 wt %, 30 wt %, 20 wt %, 10 wt % or 5 wt % of a flavor. In some cases, the amorphous solid may comprise at least about 0.5 wt %, 1 wt %, 2 wt %, 5 wt % 10 wt %, 20 wt % or 30 wt % of a flavor (all calculated on a dry weight basis). For example, the amorphous solid may comprise 0.1-60 wt %, 1-60 wt %, 5-60 wt %, 10-60 wt %, 20-50 wt % or 30-40 wt % of a flavor. In some cases, the flavor (if present) comprises, consists essentially of or consists of menthol. In some cases, the amorphous solid does not comprise a flavor.

In some embodiments, the amorphous solid comprises less than 60 wt % of a filler, such as from 1 wt % to 60 wt %, or 5 wt % to 50 wt %, or 5 wt % to 30 wt %, or 10 wt % to 20 wt %.

In other embodiments, the amorphous solid comprises less than 20 wt %, suitably less than 10 wt % or less than 5 wt % of a filler. In some cases, the amorphous solid comprises less than 1 wt % of a filler, and in some cases, comprises no filler. In some embodiments, the amorphous solid does not comprise tobacco fibers. In particular embodiments, the amorphous solid does not comprise fibrous material.

The filler, if present, may comprise one or more inorganic filler materials, such as calcium carbonate, perlite, vermiculite, diatomaceous earth, colloidal silica, magnesium oxide, magnesium sulphate, magnesium carbonate, and suitable inorganic sorbents, such as molecular sieves. The filler may comprise one or more organic filler materials such as wood pulp, cellulose and cellulose derivatives. In particular cases, the amorphous solid comprises no calcium carbonate such as chalk.

In particular embodiments which include filler, the filler is fibrous. For example, the filler may be a fibrous organic filler material such as wood pulp, hemp fiber, cellulose or cellulose derivatives. Without wishing to be bound by theory, it is believed that including fibrous filler in an amorphous solid may increase the tensile strength of the material. This may be particularly advantageous in examples wherein the amorphous solid is provided as a sheet, such as when an amorphous solid sheet circumscribes a rod of aerosolizable material.

In some cases, the aerosol generating material may consist essentially of, or consist of a starch, a plasticizer, water and optionally a plant-derived flavor or aroma component, and optionally a flavorant. In some cases, the aerosol generating material may consist essentially of, or consist of potato starch, glycerol, a tobacco material and water.

In some cases, the aerosol generating substrate may additionally comprise a carrier on which the aerosol generating material solid is provided. This carrier may ease manufacture and/or handling through, for example, (a) providing a surface onto which a slurry may be cast (and which the slurry does not need to be separated from later), (b) providing a non-tacky surface for the aerosol generating substrate easing handling, (c) providing some rigidity to the substrate.

In some cases, the carrier may be formed from materials selected from metal foil, paper, carbon paper, greaseproof paper, ceramic, carbon allotropes such as graphite and graphene, plastic, cardboard, wood or combinations thereof. In some cases, the carrier may comprise or consist of a tobacco material, such as a sheet of reconstituted tobacco. In some cases, the carrier may be formed from materials selected from metal foil, paper, cardboard, wood or combinations thereof. In some cases, the carrier itself be a laminate structure comprising layers of materials selected from the preceding lists. In some cases, the carrier may also function as a flavor carrier. For example, the carrier may be impregnated with a flavorant or with tobacco extract.

In some cases, the carrier may be substantially or wholly impermeable to gas and/or aerosol. This prevents aerosol or gas passage through the carrier in use, thereby controlling the flow and ensuring it is delivered to the user. This can also be used to prevent condensation or other deposition of the gas/aerosol in use on, for example, the surface of a heater provided in an aerosol generating assembly. Thus, consumption efficiency and hygiene can be improved in some cases.

In some cases, the carrier in the aerosol generating article may comprise or consist of a porous layer that abuts the starch matrix. For example, the porous layer may be a paper layer. In some particular cases, the starch layer is disposed in direct contact with the porous layer; the porous layer abuts the starch and forms a strong bond. The starch matrix is formed by drying a gel and, without being limited by theory, it is thought that the slurry from which the gel is formed partially impregnates the porous layer (e.g. paper) so that when the gel sets and forms cross-links, the porous layer is partially bound into the gel. This provides a strong binding between the gel and the porous layer (and between the dried gel and the porous layer).

Additionally, surface roughness may contribute to the strength of bond between the aerosol generating material and the carrier. The inventors have found that the paper roughness (for the surface abutting the carrier) may suitably be in the range of 50-1000 Bekk seconds, suitably 50-150 Bekk seconds, suitably 100 Bekk seconds (measured over an air pressure interval of 50.66-48.00 kPa). (A Bekk smoothness tester is an instrument used to determine the smoothness of a paper surface, in which air at a specified pressure is leaked between a smooth glass surface and a paper sample, and the time (in seconds) for a fixed volume of air to seep between these surfaces is the “Bekk smoothness”.)

Conversely, the surface of the carrier facing away from the aerosol generating material may be arranged in contact with the heater, and a smoother surface may provide more efficient heat transfer. Thus, in some cases, the carrier is disposed so as to have a rougher side abutting the aerosol generating material and a smoother side facing away from the aerosol generating material.

In one particular case, the carrier may be a paper-backed foil; the paper layer abuts the aerosol generating material and the properties discussed in the previous paragraphs are afforded by this abutment. The foil backing is substantially impermeable, providing control of the aerosol flow path. A metal foil backing may also serve to conduct heat to the aerosol generating material.

In another case, the foil layer of the paper-backed foil abuts the amorphous solid. The foil is substantially impermeable, thereby preventing water provided in the amorphous solid to be absorbed into the paper which could weaken its structural integrity.

In some cases, the carrier is formed from or comprises metal foil, such as aluminum foil. A metallic carrier may allow for better conduction of thermal energy to the amorphous solid. Additionally, or alternatively, a metal foil may function as a susceptor in an induction heating system. In particular embodiments, the carrier comprises a metal foil layer and a support layer, such as cardboard. In these embodiments, the metal foil layer may have a thickness of less than 20 μm, such as from about 1 μm to about 10 μm, suitably about 5 μm.

In some cases, the carrier may be magnetic. This functionality may be used to fasten the carrier to the assembly in use. In some cases, the aerosol generating substrate may comprise one or more magnets which can be used to fasten the substrate to an induction heater in use.

In some cases, the aerosol generating substrate may comprise heating means embedded in the aerosol generating material, such as resistive or inductive heating elements.

In some cases, the amorphous solid may have a thickness of about 0.015 mm to about 1.0 mm. Suitably, the thickness may be in the range of about 0.05 mm, 0.1 mm or 0.15 mm to about 0.5 mm or 0.3 mm. The inventors have found that a material having a thickness of 0.2 mm is particularly suitable. The inventors have established that if the aerosol generating material is too thick, then heating efficiency is compromised. This adversely affects the power consumption in use. Conversely, if the material is too thin, it is difficult to manufacture and handle; a very thin material is harder to cast and may be fragile, compromising aerosol formation in use. In some cases, the thickness stipulated herein is a mean thickness for the material. In some cases, the layer thickness may vary by no more than 25%, 20%, 15%, 10%, 5% or 1%.

The aerosol generating material may be formed as a sheet. It may be incorporated into the article in sheet form. In some cases, the aerosol generating material may be included as a planar sheet, as a bunched or gathered sheet, as a crimped sheet, or as a rolled sheet (i.e. in the form of a tube). In some cases, the sheet may be used as a wrapping material, which at least partially circumscribes other elements of the aerosol generating article, such as another aerosolizable material (e.g. tobacco). In some other cases, the aerosol generating material may be formed as a sheet and then shredded and incorporated into the article. In some cases, the shredded sheet may be mixed with cut rag tobacco and incorporated into the article.

The aerosol generating material comprising the amorphous solid may have any suitable area density, such as from 30 g/m² to 120 g/m². In some embodiments, aerosol generating material may have an area density of from about 30 to 70 g/m², or about 40 to 60 g/m². In some embodiments, the amorphous solid may have an area density of from about 80 to 120 g/m², or from about 70 to 110 g/m², or particularly from about 90 to 110 g/m². Such area densities may be particularly suitable where the aerosol-generating material is included in an aerosol generating article/assembly in sheet form, or as a shredded sheet (described further herein below). For example, an aerosol generating material having a mass per unit area of 80-120 g/m² has a density comparable to cut rag tobacco, and so a mixture of these components does not readily separate.

In some examples, the amorphous solid in sheet form may have a tensile strength of from around 200 N/m to around 900 N/m. In some examples, such as where the amorphous solid does not comprise a filler, the amorphous solid may have a tensile strength of from 200 N/m to 400 N/m, or 200 N/m to 300 N/m, or about 250 N/m. Such tensile strengths may be particularly suitable for embodiments wherein the aerosol generating material is formed as a sheet and then shredded and incorporated into an aerosol generating article. In some examples, such as where the amorphous solid comprises a filler, the amorphous solid may have a tensile strength of from 600 N/m to 900 N/m, or from 700 N/m to 900 N/m, or around 800 N/m. Such tensile strengths may be particularly suitable for embodiments wherein the aerosol generating material is included in an aerosol generating article/assembly as a rolled sheet, suitably in the form of a tube.

In some cases, the article may additionally comprise a filter and/or cooling element. In some cases, the aerosol generating article may be circumscribed by a wrapping material such as paper.

A second aspect of the invention provides an aerosol generating assembly comprising an aerosol generating article according to the first aspect of the invention and a heater configured to heat but not burn the aerosol generating material.

The heater may be, in some cases, a thin film, electrically resistive heater. In other cases, the heater may comprise an induction heater or the like. The heater may be a combustible heat source or a chemical heat source which undergoes an exothermic reaction to product heat in use. The aerosol generating assembly may comprise a plurality of heaters. The heater(s) may be powered by a battery.

In some cases, the heater may heat, without burning, the aerosolizable material to between 120° C. and 350° C. in use. In some cases, the heater may heat, without burning, the aerosolizable material to between 140° C. and 250° C. in use. In some cases in use, substantially all of the amorphous solid is less than about 4 mm, 3 mm, 2 mm or 1 mm from the heater. In some cases, the solid is disposed between about 0.010 mm and 2.0 mm from the heater, suitably between about 0.02 mm and 1.0 mm, suitably 0.1 mm to 0.5 mm. These minimum distances may, in some cases, reflect the thickness of a carrier that supports the amorphous solid. In some cases, a surface of the amorphous solid may directly abut the heater.

In some cases, the heater may be embedded in the aerosol generating substrate. In some such cases, the heater may be an electrically resistive heater (with exposed contacts for connection to an electrical circuit). In other such cases, the heater may be a susceptor embedded in the aerosol generating substrate, which is heated by induction.

The aerosol generating assembly may additionally comprise a cooling element and/or a filter. The cooling element, if present, may act or function to cool gaseous or aerosol components. In some cases, it may act to cool gaseous components such that they condense to form an aerosol. It may also act to space the very hot parts of the apparatus from the user. The filter, if present, may comprise any suitable filter known in the art such as a cellulose acetate plug.

In some cases, the aerosol generating assembly may be a heat-not-burn device. A heat-not-burn device is disclosed in WO 2015/062983 A2, which is incorporated by reference in its entirety. In some cases, the aerosol generating assembly may be an electronic tobacco hybrid device. An electronic tobacco hybrid device is disclosed in WO 2016/135331 A1, which is incorporated by reference in its entirety.

The aerosol generating article or assembly may additionally comprise ventilation apertures. These may be provided in the sidewall of the article. In some cases, the ventilation apertures may be provided in the filter and/or cooling element. These apertures may allow cool air to be drawn into the article during use, which can mix with the heated volatilized components thereby cooling the aerosol.

The ventilation enhances the generation of visible heated volatilized components from the article when it is heated in use. The heated volatilized components are made visible by the process of cooling the heated volatilized components such that supersaturation of the heated volatilized components occurs. The heated volatilized components then undergo droplet formation, otherwise known as nucleation, and eventually the size of the aerosol particles of the heated volatilized components increases by further condensation of the heated volatilized components and by coagulation of newly formed droplets from the heated volatilized components.

In some cases, the ratio of the cool air to the sum of the heated volatilized components and the cool air, known as the ventilation ratio, is at least 15%. A ventilation ratio of 15% enables the heated volatilized components to be made visible by the method described above. The visibility of the heated volatilized components enables the user to identify that the volatilized components have been generated and adds to the sensory experience of the smoking experience.

In another example, the ventilation ratio is between 50% and 85% to provide additional cooling to the heated volatilized components. In some cases, the ventilation ratio may be at least 60% or 65%.

The assembly may comprise an integrated aerosol generating article and heater. For example, the integrated heater may be a combustible or chemical heat source the heats the aerosol generating substrate, without burning, in use. Alternatively, the assembly may comprise a heater device into which the article is inserted in use, wherein the heater is configured to heat but not burn the aerosol generating substrate.

Referring to FIGS. 1 and 2, there are shown a partially cut-away section view and a perspective view of an example of an aerosol generating article 101. The article 101 is adapted for use with a device having a power source and a heater. The article 101 of this embodiment is particularly suitable for use with the device 51 shown in FIGS. 5 to 7, described below. In use, the article 101 may be removably inserted into the device shown in FIG. 5 at an insertion point 20 of the device 51.

The article 101 of one example is in the form of a substantially cylindrical rod that includes a body of aerosol generating material 103 and a filter assembly 105 in the form of a rod. The aerosol generating material comprises the starch matrix material described herein. In some embodiments, it may be included in sheet form. In some embodiments it may be included in the form of a shredded sheet. In some embodiments, the aerosol generating material described herein may be incorporated in sheet form and in shredded form.

The filter assembly 105 includes three segments, a cooling segment 107, a filter segment 109 and a mouth end segment 111. The article 101 has a first end 113, also known as a mouth end or a proximal end and a second end 115, also known as a distal end. The body of aerosol generating material 103 is located towards the distal end 115 of the article 101. In one example, the cooling segment 107 is located adjacent the body of aerosol generating material 103 between the body of aerosol generating material 103 and the filter segment 109, such that the cooling segment 107 is in an abutting relationship with the aerosol generating material 103 and the filter segment 103. In other examples, there may be a separation between the body of aerosol generating material 103 and the cooling segment 107 and between the body of aerosol generating material 103 and the filter segment 109. The filter segment 109 is located in between the cooling segment 107 and the mouth end segment 111. The mouth end segment 111 is located towards the proximal end 113 of the article 101, adjacent the filter segment 109. In one example, the filter segment 109 is in an abutting relationship with the mouth end segment 111. In one embodiment, the total length of the filter assembly 105 is between 37 mm and 45 mm, more preferably, the total length of the filter assembly 105 is 41 mm.

In one example, the rod of aerosol generating material 103 is between 34 mm and 50 mm in length, suitably between 38 mm and 46 mm in length, suitably 42 mm in length.

In one example, the total length of the article 101 is between 71 mm and 95 mm, suitably between 79 mm and 87 mm, suitably 83 mm.

An axial end of the body of aerosol generating material 103 is visible at the distal end 115 of the article 101. However, in other embodiments, the distal end 115 of the article 101 may comprise an end member (not shown) covering the axial end of the body of aerosol generating material 103.

The body of aerosol generating material 103 is joined to the filter assembly 105 by annular tipping paper (not shown), which is located substantially around the circumference of the filter assembly 105 to surround the filter assembly 105 and extends partially along the length of the body of aerosol generating material 103. In one example, the tipping paper is made of 58 GSM standard tipping base paper. In one example the tipping paper has a length of between 42 mm and 50 mm, suitably of 46 mm.

In one example, the cooling segment 107 is an annular tube and is located around and defines an air gap within the cooling segment. The air gap provides a chamber for heated volatilized components generated from the body of aerosol generating material 103 to flow.

The cooling segment 107 is hollow to provide a chamber for aerosol accumulation yet rigid enough to withstand axial compressive forces and bending moments that might arise during manufacture and whilst the article 101 is in use during insertion into the device 51. In one example, the thickness of the wall of the cooling segment 107 is approximately 0.29 mm.

The cooling segment 107 provides a physical displacement between the aerosol generating material 103 and the filter segment 109. The physical displacement provided by the cooling segment 107 will provide a thermal gradient across the length of the cooling segment 107. In one example the cooling segment 107 is configured to provide a temperature differential of at least 40 degrees Celsius between a heated volatilized component entering a first end of the cooling segment 107 and a heated volatilized component exiting a second end of the cooling segment 107. In one example the cooling segment 107 is configured to provide a temperature differential of at least 60 degrees Celsius between a heated volatilized component entering a first end of the cooling segment 107 and a heated volatilized component exiting a second end of the cooling segment 107. This temperature differential across the length of the cooling element 107 protects the temperature sensitive filter segment 109 from the high temperatures of the aerosol generating material 103 when it is heated by the device 51. If the physical displacement was not provided between the filter segment 109 and the body of aerosol generating material 103 and the heating elements of the device 51, then the temperature sensitive filter segment may 109 become damaged in use, so it would not perform its required functions as effectively.

In one example the length of the cooling segment 107 is at least 15 mm. In one example, the length of the cooling segment 107 is between 20 mm and 30 mm, more particularly 23 mm to 27 mm, more particularly 25 mm to 27 mm, suitably 25 mm.

The cooling segment 107 is made of paper, which means that it is comprised of a material that does not generate compounds of concern, for example, toxic compounds when in use adjacent to the heater of the device 51. In one example, the cooling segment 107 is manufactured from a spirally wound paper tube which provides a hollow internal chamber yet maintains mechanical rigidity. Spirally wound paper tubes are able to meet the tight dimensional accuracy requirements of high-speed manufacturing processes with respect to tube length, outer diameter, roundness and straightness.

In another example, the cooling segment 107 is a recess created from stiff plug wrap or tipping paper. The stiff plug wrap or tipping paper is manufactured to have a rigidity that is sufficient to withstand the axial compressive forces and bending moments that might arise during manufacture and whilst the article 101 is in use during insertion into the device 51.

The filter segment 109 may be formed of any filter material sufficient to remove one or more volatilized compounds from heated volatilized components from the aerosol generating material. In one example the filter segment 109 is made of a mono-acetate material, such as cellulose acetate. The filter segment 109 provides cooling and irritation-reduction from the heated volatilized components without depleting the quantity of the heated volatilized components to an unsatisfactory level for a user.

In some embodiments, a capsule (not illustrated) may be provided in filter segment 109. It may be disposed substantially centrally in the filter segment 109, both across the filter segment 109 diameter and along the filter segment 109 length. In other cases, it may be offset in one or more dimension. The capsule may in some cases, where present, contain a volatile component such as a flavorant or aerosol generating agent.

The density of the cellulose acetate tow material of the filter segment 109 controls the pressure drop across the filter segment 109, which in turn controls the draw resistance of the article 101. Therefore the selection of the material of the filter segment 109 is important in controlling the resistance to draw of the article 101. In addition, the filter segment performs a filtration function in the article 101.

In one example, the filter segment 109 is made of a 8Y15 grade of filter tow material, which provides a filtration effect on the heated volatilized material, whilst also reducing the size of condensed aerosol droplets which result from the heated volatilized material.

The presence of the filter segment 109 provides an insulating effect by providing further cooling to the heated volatilized components that exit the cooling segment 107. This further cooling effect reduces the contact temperature of the user's lips on the surface of the filter segment 109.

In one example, the filter segment 109 is between 6 mm to 10 mm in length, suitably 8 mm.

The mouth end segment 111 is an annular tube and is located around and defines an air gap within the mouth end segment 111. The air gap provides a chamber for heated volatilized components that flow from the filter segment 109. The mouth end segment 111 is hollow to provide a chamber for aerosol accumulation yet rigid enough to withstand axial compressive forces and bending moments that might arise during manufacture and whilst the article is in use during insertion into the device 51. In one example, the thickness of the wall of the mouth end segment 111 is approximately 0.29 mm. In one example, the length of the mouth end segment 111 is between 6 mm to 10 mm, suitably 8 mm.

The mouth end segment 111 may be manufactured from a spirally wound paper tube which provides a hollow internal chamber yet maintains critical mechanical rigidity. Spirally wound paper tubes are able to meet the tight dimensional accuracy requirements of high-speed manufacturing processes with respect to tube length, outer diameter, roundness and straightness.

The mouth end segment 111 provides the function of preventing any liquid condensate that accumulates at the exit of the filter segment 109 from coming into direct contact with a user.

It should be appreciated that, in one example, the mouth end segment 111 and the cooling segment 107 may be formed of a single tube and the filter segment 109 is located within that tube separating the mouth end segment 111 and the cooling segment 107.

Referring to FIGS. 3 and 4, there are shown a partially cut-away section and perspective views of an example of an article 301. The reference signs shown in FIGS. 3 and 4 are equivalent to the reference signs shown in FIGS. 1 and 2, but with an increment of 200.

In the example of the article 301 shown in FIGS. 3 and 4, a ventilation region 317 is provided in the article 301 to enable air to flow into the interior of the article 301 from the exterior of the article 301. In one example the ventilation region 317 takes the form of one or more ventilation holes 317 formed through the outer layer of the article 301. The ventilation holes may be located in the cooling segment 307 to aid with the cooling of the article 301. In one example, the ventilation region 317 comprises one or more rows of holes, and preferably, each row of holes is arranged circumferentially around the article 301 in a cross-section that is substantially perpendicular to a longitudinal axis of the article 301.

In one example, there are between one to four rows of ventilation holes to provide ventilation for the article 301. Each row of ventilation holes may have between 12 to 36 ventilation holes 317. The ventilation holes 317 may, for example, be between 100 to 500 μm in diameter. In one example, an axial separation between rows of ventilation holes 317 is between 0.25 mm and 0.75 mm, suitably 0.5 mm.

In one example, the ventilation holes 317 are of uniform size. In another example, the ventilation holes 317 vary in size. The ventilation holes can be made using any suitable technique, for example, one or more of the following techniques: laser technology, mechanical perforation of the cooling segment 307 or pre-perforation of the cooling segment 307 before it is formed into the article 301. The ventilation holes 317 are positioned so as to provide effective cooling to the article 301.

In one example, the rows of ventilation holes 317 are located at least 11 mm from the proximal end 313 of the article, suitably between 17 mm and 20 mm from the proximal end 313 of the article 301. The location of the ventilation holes 317 is positioned such that user does not block the ventilation holes 317 when the article 301 is in use.

Providing the rows of ventilation holes between 17 mm and 20 mm from the proximal end 313 of the article 301 enables the ventilation holes 317 to be located outside of the device 51, when the article 301 is fully inserted in the device 51, as can be seen in FIGS. 6 and 7. By locating the ventilation holes outside of the device, non-heated air is able to enter the article 301 through the ventilation holes from outside the device 51 to aid with the cooling of the article 301.

The length of the cooling segment 307 is such that the cooling segment 307 will be partially inserted into the device 51, when the article 301 is fully inserted into the device 51. The length of the cooling segment 307 provides a first function of providing a physical gap between the heater arrangement of the device 51 and the heat sensitive filter arrangement 309, and a second function of enabling the ventilation holes 317 to be located in the cooling segment, whilst also being located outside of the device 51, when the article 301 is fully inserted into the device 51. As can be seen from FIGS. 6 and 7, the majority of the cooling element 307 is located within the device 51. However, there is a portion of the cooling element 307 that extends out of the device 51. It is in this portion of the cooling element 307 that extends out of the device 51 in which the ventilation holes 317 are located.

Referring now to FIGS. 5 to 7 in more detail, there is shown an example of a device 51 arranged to heat aerosol generating material to volatilize at least one component of said aerosol generating material, typically to form an aerosol which can be inhaled. The device 51 is a heating device which releases compounds by heating, but not burning, the aerosol generating material.

A first end 53 is sometimes referred to herein as the mouth or proximal end 53 of the device 51 and a second end 55 is sometimes referred to herein as the distal end 55 of the device 51. The device 51 has an on/off button 57 to allow the device 51 as a whole to be switched on and off as desired by a user.

The device 51 comprises a housing 59 for locating and protecting various internal components of the device 51. In the example shown, the housing 59 comprises a uni-body sleeve 11 that encompasses the perimeter of the device 51, capped with a top panel 17 which defines generally the ‘top’ of the device 51 and a bottom panel 19 which defines generally the ‘bottom’ of the device 51. In another example the housing comprises a front panel, a rear panel and a pair of opposite side panels in addition to the top panel 17 and the bottom panel 19.

The top panel 17 and/or the bottom panel 19 may be removably fixed to the uni-body sleeve 11, to permit easy access to the interior of the device 51, or may be “permanently” fixed to the uni-body sleeve 11, for example to deter a user from accessing the interior of the device 51. In an example, the panels 17 and 19 are made of a plastics material, including for example glass-filled nylon formed by injection molding, and the uni-body sleeve 11 is made of aluminum, though other materials and other manufacturing processes may be used.

The top panel 17 of the device 51 has an opening 20 at the mouth end 53 of the device 51 through which, in use, the article 101, 301 including the aerosol generating material may be inserted into the device 51 and removed from the device 51 by a user.

The housing 59 has located or fixed therein a heater arrangement 23, control circuitry 25 and a power source 27. In this example, the heater arrangement 23, the control circuitry 25 and the power source 27 are laterally adjacent (that is, adjacent when viewed from an end), with the control circuitry 25 being located generally between the heater arrangement 23 and the power source 27, though other locations are possible.

The control circuitry 25 may include a controller, such as a microprocessor arrangement, configured and arranged to control the heating of the aerosol generating material in the article 101, 301 as discussed further below.

The power source 27 may be for example a battery, which may be a rechargeable battery or a non-rechargeable battery. Examples of suitable batteries include for example a lithium-ion battery, a nickel battery (such as a nickel-cadmium battery), an alkaline battery and/or the like. The battery 27 is electrically coupled to the heater arrangement 23 to supply electrical power when required and under control of the control circuitry 25 to heat the aerosol generating material in the article (as discussed, to volatilize the aerosol generating material without causing the aerosol generating material to burn).

An advantage of locating the power source 27 laterally adjacent to the heater arrangement 23 is that a physically large power source 25 may be used without causing the device 51 as a whole to be unduly lengthy. As will be understood, in general a physically large power source 25 has a higher capacity (that is, the total electrical energy that can be supplied, often measured in Amp-hours or the like) and thus the battery life for the device 51 can be longer.

In one example, the heater arrangement 23 is generally in the form of a hollow cylindrical tube, having a hollow interior heating chamber 29 into which the article 101, 301 comprising the aerosol generating material is inserted for heating in use. Different arrangements for the heater arrangement 23 are possible. For example, the heater arrangement 23 may comprise a single heating element or may be formed of plural heating elements aligned along the longitudinal axis of the heater arrangement 23. The or each heating element may be annular or tubular, or at least part-annular or part-tubular around its circumference. In an example, the or each heating element may be a thin film heater. In another example, the or each heating element may be made of a ceramics material. Examples of suitable ceramics materials include alumina and aluminum nitride and silicon nitride ceramics, which may be laminated and sintered. Other heating arrangements are possible, including for example inductive heating, infrared heater elements, which heat by emitting infrared radiation, or resistive heating elements formed by for example a resistive electrical winding.

In one particular example, the heater arrangement 23 is supported by a stainless steel support tube and comprises a polyimide heating element. The heater arrangement 23 is dimensioned so that substantially the whole of the body of aerosol generating material 103, 303 of the article 101, 301 is inserted into the heater arrangement 23 when the article 101, 301 is inserted into the device 51.

The or each heating element may be arranged so that selected zones of the aerosol generating material can be independently heated, for example in turn (over time, as discussed above) or together (simultaneously) as desired.

The heater arrangement 23 in this example is surrounded along at least part of its length by a thermal insulator 31. The insulator 31 helps to reduce heat passing from the heater arrangement 23 to the exterior of the device 51. This helps to keep down the power requirements for the heater arrangement 23 as it reduces heat losses generally. The insulator 31 also helps to keep the exterior of the device 51 cool during operation of the heater arrangement 23. In one example, the insulator 31 may be a double-walled sleeve which provides a low pressure region between the two walls of the sleeve. That is, the insulator 31 may be for example a “vacuum” tube, i.e. a tube that has been at least partially evacuated so as to minimize heat transfer by conduction and/or convection. Other arrangements for the insulator 31 are possible, including using heat insulating materials, including for example a suitable foam-type material, in addition to or instead of a double-walled sleeve.

The housing 59 may further comprises various internal support structures 37 for supporting all internal components, as well as the heating arrangement 23.

The device 51 further comprises a collar 33 which extends around and projects from the opening 20 into the interior of the housing 59 and a generally tubular chamber 35 which is located between the collar 33 and one end of the vacuum sleeve 31. The chamber 35 further comprises a cooling structure 35 f, which in this example, comprises a plurality of cooling fins 35 f spaced apart along the outer surface of the chamber 35, and each arranged circumferentially around outer surface of the chamber 35. There is an air gap 36 between the hollow chamber 35 and the article 101, 301 when it is inserted in the device 51 over at least part of the length of the hollow chamber 35. The air gap 36 is around all of the circumference of the article 101, 301 over at least part of the cooling segment 307.

The collar 33 comprises a plurality of ridges 60 arranged circumferentially around the periphery of the opening 20 and which project into the opening 20. The ridges 60 take up space within the opening 20 such that the open span of the opening 20 at the locations of the ridges 60 is less than the open span of the opening 20 at the locations without the ridges 60. The ridges 60 are configured to engage with an article 101, 301 inserted into the device to assist in securing it within the device 51. Open spaces (not shown in the Figures) defined by adjacent pairs of ridges 60 and the article 101, 301 form ventilation paths around the exterior of the article 101, 301. These ventilation paths allow hot vapors that have escaped from the article 101, 301 to exit the device 51 and allow cooling air to flow into the device 51 around the article 101, 301 in the air gap 36.

In operation, the article 101, 301 is removably inserted into an insertion point 20 of the device 51, as shown in FIGS. 5 to 7. Referring particularly to FIG. 6, in one example, the body of aerosol generating material 103, 303, which is located towards the distal end 115, 315 of the article 101, 301, is entirely received within the heater arrangement 23 of the device 51.

The proximal end 113, 313 of the article 101, 301 extends from the device 51 and acts as a mouthpiece assembly for a user.

In operation, the heater arrangement 23 will heat the article 101, 301 to volatilize at least one component of the aerosol generating material from the body of aerosol generating material 103, 303.

The primary flow path for the heated volatilized components from the body of aerosol generating material 103, 303 is axially through the article 101, 301, through the chamber inside the cooling segment 107, 307, through the filter segment 109, 309, through the mouth end segment 111, 313 to the user. In one example, the temperature of the heated volatilized components that are generated from the body of aerosol generating material is between 60° C. and 250° C., which may be above the acceptable inhalation temperature for a user. As the heated volatilized component travels through the cooling segment 107, 307, it will cool and some volatilized components will condense on the inner surface of the cooling segment 107, 307.

In the examples of the article 301 shown in FIGS. 3 and 4, cool air will be able to enter the cooling segment 307 via the ventilation holes 317 formed in the cooling segment 307. This cool air will mix with the heated volatilized components to provide additional cooling to the heated volatilized components.

A third aspect of the invention provides starch matrix material comprising;

-   -   a plasticizer wherein the amount of plasticizer is from about 5%         to 70% by weight of the starch; and     -   a plant-derived flavor or aroma component.

Features described herein in relation to the “aerosol generating material” are hereby explicating disclosed in combination with the third aspect of the invention.

Suitably, the plant-derived flavor or aroma component comprises a tobacco material, such as a tobacco extract.

Suitably, the plant-derived flavor or aroma component may be a powdered component, added in an amount 40% to 300% by weight of the starch.

The invention also provides a method of making an aerosol generating article according to the first aspect, the method comprising;

(i) mixing the constituent parts of the aerosol generating material in a slurry, heating and stirring the slurry to effect gelation, casting the gel and drying by heating to form the aerosol generating material; and

(ii) incorporating the aerosol generating material in an aerosol generating article.

In some cases, the heating and stirring step may involve heating to around 70-100° C., suitably 85° C. for up to about 20 minutes. The drying step may involve heating around 30-70° C., suitably 50° C., for 1-5 hours, suitably around 3 hours.

The method may include an additional step comprising shredding the aerosol generating material, before it is incorporated into an aerosol generating article.

The invention also provides a slurry comprising:

-   -   a starch;     -   a plasticizer wherein the amount of plasticizer is from about 5%         to 70% by weight of the starch; and     -   a plant-derived flavor or aroma component; and     -   water.

Suitably, the weight ratio of water to the total weight of the other ingredients is between about 10:1 and 20:1.

In some examples, the slurry has a viscosity of from about 10 to about 20 Pa·s at 46.5° C., such as from about 14 to about 16 Pa·s at 46.5° C.

The invention also provides a slurry comprising:

-   -   a starch;     -   a plasticizer, wherein the amount of plasticizer is from about         5% to 70% by weight of the starch;     -   a powdered tobacco material having a mean particle diameter of         less than about 250 μm, wherein the amount of powdered tobacco         material is from about 40% to 300% by weight of the starch;     -   water, wherein the weight ratio of water to the total weight of         the other ingredients is between about 10:1 and 20:1.

The invention also provides a slurry comprising

-   -   a starch;     -   a plasticizer, wherein the amount of plasticizer is from about         5% to 70% by weight of the starch;     -   a aqueous tobacco extract, wherein the weight ratio of the         aqueous tobacco extract to the total weight of the other         ingredients is between about 10:1 and 20:1.

Further aspects of the invention include;

-   -   (iii) a wrapper for a smoking article or aerosol generating         article, wherein the wrapper comprises a starch matrix and a         plasticizer, wherein the amount of plasticizer is from about 5%         to 30% by weight of the starch; and     -   (iv) a filter for a smoking article or aerosol generating         article, the filter comprising a starch matrix and a         plasticizer, wherein the amount of plasticizer is from about 5%         to 15% by weight of the starch.

The inventors have established that these starch matrix materials find application as filters and wrappers, in addition to as an aerosol generating material.

The invention also provides articles including the above wrapper and/or filter.

EXAMPLES Example 1

A starch matrix film was prepared as follows:

1000 mg of potato starch, 300 mg glycerol and 20 mL water were added to a 50mL beaker. The slurry was stirred using a stirring bar and the mixture was heated to 85° C. under vigorous stirring vigorously for 10 min. Thickening (or gelation) of the mixture was observed.

The gel was cast onto a PTFE sheet. (The gel is very polar so it will stick strongly to glass or metal.) The material was dried for 2 hrs @ 50° C. to generate a film having a thickness of 4 mm.

Example 2

In another example, a starch matrix film was made using the process of example 1, with the addition of 500-2000 mg of tobacco powder (particle size 200 μm) to the mixture prior to stirring.

Example 3

In another example, a starch matrix film was made using the process of example 1, except that the water was replaced with 20 mL of aqueous tobacco extract (obtained by extraction of ground Virginia tobacco with deionized water) and 450 mg of glycerol was used (rather than 300 mg).

Testing

The materials of each example will be heated, without burning, in a simulated puff regime (heating to 250° C., 2 second puffs taken every 30 seconds under a 1.65 L/min airflow).

Definitions

The active substance as used herein may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.

In some embodiments, the active substance comprises nicotine.

In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.

As noted herein, the active substance may comprise one or more constituents, derivatives or extracts of cannabis, such as one or more cannabinoids or terpenes.

Cannabinoids are a class of natural or synthetic chemical compounds which act on cannabinoid receptors (i.e., CB1 and CB2) in cells that repress neurotransmitter release in the brain. Cannabinoids may be naturally occurring (phytocannabinoids) from plants such as cannabis, from animals (endocannabinoids), or artificially manufactured (synthetic cannabinoids). Cannabis species express at least 85 different phytocannabinoids, and are divided into subclasses, including cannabigerols, cannabichromenes, cannabidiols, tetrahydrocannabinols, cannabinols and cannabinodiols, and other cannabinoids. Cannabinoids found in cannabis include, without limitation: cannabigerol (CBG), cannabichromene (CBC), cannabidiol (CBD), tetrahydrocannabinol (THC), cannabinol (CBN), cannabinodiol (CBDL), cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethyl ether (CBGM), cannabinerolic acid, cannabidiolic acid (CBDA), Cannabinol propyl variant (CBNV), cannabitriol (CBO), tetrahydrocannabmolic acid (THCA), and tetrahydrocannabivarinic acid (THCV A).

As noted herein, the active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term “botanical” includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres fibers, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like. Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha arvensis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v., Mentha spicata crispa, Mentha cordifolia, Mentha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens.

In some embodiments, the botanical is selected from eucalyptus, star anise, cocoa and hemp.

In some embodiments, the botanical is selected from rooibos and fennel.

As used herein, the terms “flavor” and “flavorant” refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. They may include naturally occurring flavor materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavor enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gas.

The flavor may suitably comprise one or more mint-flavors suitably a mint oil from any species of the genus Mentha. The flavor may suitably comprise, consist essentially of or consist of menthol.

In some embodiments, the flavor comprises menthol, spearmint and/or peppermint.

In some embodiments, the flavor comprises flavor components of cucumber, blueberry, citrus fruits and/or redberry.

In some embodiments, the flavor comprises eugenol.

In some embodiments, the flavor comprises flavor components extracted from tobacco.

In some embodiments, the flavor comprises flavor components extracted from cannabis.

In some embodiments, the flavor may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucalyptol, WS-3.

As used herein, the term “aerosol generating agent” refers to an agent that promotes the generation of an aerosol. An aerosol generating agent may promote the generation of an aerosol by promoting an initial vaporization and/or the condensation of a gas to an inhalable solid and/or liquid aerosol.

As used herein, the term “tobacco material” refers to any material comprising tobacco or derivatives therefore. The term “tobacco material” may include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes. The tobacco material may comprise one or more of ground tobacco, tobacco fiber, cut tobacco, extruded tobacco, tobacco stem, reconstituted tobacco and/or tobacco extract.

The tobacco used to produce tobacco material may be any suitable tobacco, such as single grades or blends, cut rag or whole leaf, including Virginia and/or Burley and/or Oriental. It may also be tobacco particle ‘fines’ or dust, expanded tobacco, stems, expanded stems, and other processed stem materials, such as cut rolled stems. The tobacco material may be a ground tobacco or a reconstituted tobacco material. The reconstituted tobacco material may comprise tobacco fibers, and may be formed by casting, a Fourdrinier-based paper making-type approach with back addition of tobacco extract, or by extrusion.

All percentages by weight described herein (denoted wt %) are calculated on a dry weight basis, unless explicitly stated otherwise. All weight ratios are also calculated on a dry weight basis. A weight quoted on a dry weight basis refers to the whole of the extract or slurry or material, other than the water, and may include components which by themselves are liquid at room temperature and pressure, such as glycerol. Conversely, a weight percentage quoted on a wet weight basis refers to all components, including water.

For the avoidance of doubt, where in this specification the term “comprises” is used in defining the invention or features of the invention, embodiments are also disclosed in which the invention or feature can be defined using the terms “consists essentially of” or “consists of” in place of “comprises”. Reference to a material “comprising” certain features means that those features are included in, contained in, or held within the material.

The above embodiments are to be understood as illustrative examples of the invention. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims. 

1. An aerosol generating article for use in an aerosol generating assembly, the article comprising an aerosol generating substrate comprising an aerosol generating material, wherein the aerosol generating material is solid and comprises a starch and a plasticizer, wherein the amount of plasticizer is from about 5% to 70% by weight of the starch.
 2. The aerosol generating article according to claim 1, wherein the amount of plasticizer is from about 20% to 50% by weight of the starch.
 3. The aerosol generating article according to claim 1, wherein the aerosol generating material further comprises a tobacco material.
 4. The aerosol generating article according to claim 3, wherein the tobacco material comprises a powdered tobacco material having a particle size of less than about 250 μm.
 5. The aerosol generating article according to claim 3, wherein the tobacco material comprises a tobacco extract.
 6. The aerosol generating article according to claim 1, wherein the plasticizer is selected from erythritol, sorbitol, glycerol, glycols such as propylene glycol, monohydric alcohols, high boiling point hydrocarbons, lactic acid, diacetin, triacetin, triethylene glycol diacetate, triethyl citrate, ethyl myristate, isopropyl myristate, methyl stearate, dimethyl dodecanedioate and dimethyl tetradecanedioate.
 7. The aerosol generating article according to claim 1, wherein the starch comprises potato starch.
 8. The aerosol generating article according to claim 1, wherein the solid aerosol generating material is formed as a sheet.
 9. The aerosol generating article according to claim 1, wherein the aerosol generating material has a mass per unit area of 80-120 g/m².
 10. The aerosol generating article according to claim 1, wherein the aerosol generating substrate comprises a carrier on which the aerosol generating material is provided.
 11. An aerosol generating assembly comprising the aerosol generating article according claim 1 and a heater configured to heat the aerosol generating material without burning the aerosol generating material.
 12. A starch matrix material comprising; a plasticizer wherein the amount of plasticizer is from about 5% to 70% by weight of the starch; and a plant-derived flavor or aroma component.
 13. A kit comprising the aerosol generating article according to claim 1 and a device which is configured to receive the article in use, the device comprising a heater which is configured to heat the aerosol generating material without burning the aerosol generating material during use.
 14. A method of making the aerosol generating article of claim 1, the method comprising; (i) mixing the constituent parts of the aerosol generating material in a slurry, heating and stirring the slurry to effect gelation, casting the gel and drying by heating to form the aerosol generating material; and (ii) incorporating the aerosol generating material in the aerosol generating article.
 15. A slurry comprising: a starch; a plasticizer wherein the amount of plasticizer is from about 5% to 70% by weight of the starch; and a plant-derived flavor or aroma component; and water, wherein a weight ratio of water to a total weight of other ingredients is between about 10:1 and 20:1.
 16. A slurry comprising: a starch; a plasticizer, wherein the amount of plasticizer is from about 5% to 70% by weight of the starch; a powdered tobacco material having a mean particle diameter of less than about 250 μm, wherein an amount of powdered tobacco material is from about 40% to 300% by weight of the starch; and water, wherein a weight ratio of water to a total weight of other ingredients is between about 10:1 and 20:1.
 17. A slurry comprising: a starch; a plasticizer, wherein an amount of plasticizer is from about 5% to 70% by weight of the starch; and an aqueous tobacco extract, wherein a weight ratio of the aqueous tobacco extract to a total weight of other ingredients is between about 10:1 and 20:1.
 18. A smoking article comprising a wrapper, wherein the wrapper comprises a starch matrix and a plasticizer, wherein the amount of plasticizer is from about 5% to 30% by weight of the starch and wherein the smoking article is a combustible or a non-combustible smoking article.
 19. A filter for a smoking article, the filter comprising a starch matrix and a plasticizer, wherein the amount of plasticizer is from about 5% to 15% by weight of the starch and the smoking article is a combustible or non-combustible smoking article.
 20. A smoking article or aerosol generating article comprising the filter according to claim
 19. 